Lab Report
Paper details:
Use IMRD format. All this should be typed except some figures (not tables, and not graphs of results) may be drawn and scanned. Sample calculations may be scanned and attached after the IMRD part of the report, as if they were an appendix. Intro. provide the purpose of the lab and key results. The “problem” is your boss wants to know how accurate the formula is as an estimate of drain time. Methods. Describe the methods and equipment you used. A sketch may help; it may be handdrawn and scanned. Results. Include the table of data. Tables must have captions Discussion. Discuss the implications of your experiment as indicated above in the “conclusions” and “sensitivity analysis” sections. Sensitivity analysis. A sensitivity analysis is another way to determine uncertainties. Use your best trial, and show your work on a separate piece of paper (not part of main report). 1.) Assume that Dt/Dj is 5 % bigger. This means multiply Dt/Dj by 1.05 and put it into the formula and figure out the theoretical time. Is this closer or farther away from your measured time? 2.) Now assume that Dt/Dj is 5 % smaller. This means multiply Dt/Dj by 0.95 and put it into the formula and figure out the theoretical time. Is this closer or farther away from your measured time? 3.) Assume that the heights are 5% bigger. Multi h1 and h2 by 1.05 and repeat your calculations (using the Dt/Dj that you originally measured). Is the calculated time closer or farther away from your measured time? 4.) Assume that the heights are 5% smaller. Multi h1 and h2 by 0.95 and repeat your calculations (using the Dt/Dj that you originally measured). Is the calculated time closer or farther away from your measured time? Conclusions. No experiment gives 0% error. But based upon the error you see, what do you think could improve the error? How does using pails (vs. say, measuring cups) help with error? Was the size of the pail the largest contributor to the error? Does this experiment demonstrate the time to drain the tank formula? Were there any assumptions used to derive the formula that were not 100% accurate in practice? Should you have measured the volume of the water that is drained? How would you measure it and how would you incorporate this measurement into this lab? Based upon your sensitivity analysis, which variable makes the biggest difference in the time to drain the pail, the ratio of the areas of the tank to the hole, or the height? Please explain. Based upon this analysis, how would you change this experiment? Find a way to measure the volumetric flow rate. Calculate the velocity at the top of the water and the velocity at the small opening. Compare the two numbers and comment on assumptions we make about big tanks. Be sure to describe your calculation procedure in this part.
